1. Field of the Invention
The present invention relates generally to data storage subsystems, and more particularly to cached disk arrays. The invention specifically relates to network file servers.
2. Background Art
Mainframe data processing, and more recently distributed computing, have required increasingly large amounts of data storage. This data storage is most economically provided by an array of low-cost disk drives integrated with a large semiconductor cache memory. Such integrated cached disk arrays were originally introduced for use with IBM compatible host computers. A channel director in the integrated cached disk array executed channel commands received over a channel from the host computer. More recently, a network attachment has been proposed for interfacing the integrated cached disk array to a network. The network attachment, for example, is a computer programmed to communicate with clients on a network by following a network communication protocol, and to communicate with the integrated cached disk array by issuing channel commands. Although this approach has the advantage of using a conventional integrated cached disk array, the capabilities of the integrated cached disk array are under utilized in this configuration, because the network attachment is a bottleneck to data access.